1. Cells and Tissues
Subtitle

2. Review Hierarchy of life:
atoms - molecules - organelles - cells - tissues - organs - organ systems
FOCUS: tissues - organs - organ systems
TISSUES: groups of cells with a common structure and function
- different types = different structure = different function
- different types are organized to form organs

3. Four Types of Tissue
1. Epithelial 2. Connective 3. Nervous 4. Muscle

4. Epithelial
tightly packed sheets that form the outer layers and linings of internal organs Structure: closely joined cells: desmosomes and tight junctions free surface: exposed to air or fluid basement membrane: dense mat of extracellular matrix

6. Functions Functions: 1. Protection: mechanical injury
defense against microorganisms
fluid loss
2. Absorption of nutrients
3. Secretion of materials (glandular)
digestive substances: enzymes, acids, bases, mucus
mucus membranes: digestive and respiratory
oils
sweat

8. Types
Types: Simple - single layer Stratified - multiple layers Psuedostratified - one layer of different sizes Squamous - flat Cuboidal - cube Columnar – columns

13. Skin

14. CONNECTIVE:
support and bind other tissues together
Structure:
liquid, jelly like or solid (fibers)
Fibers:
collagenous - made of collagen - non-elastic - hold tissues together
elastic - made of elastin - allow for movement of tissue and retains the shape
reticular - bind tissues together

15. Types of Connective Tissue
Loose: weave of fibers holds organs in place binds to epithelial tissue

16. Loose Connective Tissue

17. Areolar Tissue

18. Adipose: fat cells storage, insulation and protection

19. Fibrous:
densely packed collagen fibers -
Forms:
Tendons: muscle to bone
achilles tendon: calf to heel
Ligaments: bone to bone at joints
L = like = bone and bone

25. Cartilage: collagen fibers and chondroitin sulfate made by choanocytes -strong yet flexible

26. Bone: mineralized connective tissue Osteoblasts: converts cartilage to bone - deposite calcium, magnesium and phosphate Haversian Systems: concentric layers of mineralized matrix - central canal - in large bones = marrow - lacuna - contain osteocytes - bone cells - matrix – mineralized portion

29. Blood: fluid connective tissue plasma - water, salts and liquid proteins erythrocytes - RBC - carry oxygen leukocytes - WBC - immune response macrophages platelets - blood clotting

32. NERVOUS: sense stimuli and transmit signals from one area to another STRUCTURE: Neuron - nerve cell - transmits nerve impulse

34. MUSCLE: movement and protection Structure: microfilaments of actin and myosin Types: Skelatal: - voluntary movement striated: overlapping filaments = stripes Cardiac: - involuntary - contractile wall of heart - striated and branched - intercalated discs: transmit signals Smooth: - no striations - line internal organs (digestive, bladder, arteries) - contract to move materials

39. ORGANS: Interdependent - Function together - dependent on one another Overall Function: HOMEOSTASIS - maintaining the steady state of bodily functions - Bioenergetics: derivation of energy - - heterotrophic - metabolism - rate animal uses energy Basal Metabolic Rate (BMR) - calories needed simply to function and stay alive

40. REGULATING INTERNAL ENVIRONMENT: internal environment surrounding the cells = interstitial fluid - fluid that surrounds each cell in the extracellular space BASIC SYSTEMS OF HOMEOSTASIS: Digestive Circulatory Excretory Respiratory All Controlled by the Nervous and Endocrine

41. Respiratory
system
Circulatory
system
Digestive
system
Excretory
system

43. Basis of Homeostasis Control: Feedback Loops Receptors: detects a change Control Center: processes information - sends message Effector: Directs response to deal with change

44. Types of Regulation: Positive: change triggers an amplifying response Labor Negative: change triggers a counteractive response - typical control Thermoregulation: Body temp Hypothalmus Sweat

45. Internal body temperature
Thermostat in
hypothalamus
activates cooling
mechanisms.
Sweat glands secrete
sweat that evaporates,
cooling the body.
Blood vessels
in skin dilate:
capillaries fill
with warm blood;
heat radiates from
skin surface.
Body temperature
decreases;
thermostat
shuts off cooling
Increased body
temperature (such
as when exercising
or in hot
surroundings)
Homeostasis:
Internal body temperature
of approximately 36–38C
increases;
shuts off warming
Decreased body
temperature
(such as when
in cold
Blood vessels in skin
constrict, diverting blood
from skin to deeper tissues
and reducing heat loss
from skin surface.
Skeletal muscles rapidly
contract, causing shivering,
which generates heat.
activates
warming

46. Response
No heat
produced
Room
temperature
decreases
Heater
turned
off
Set point
Too
hot
Set
point
Control center:
thermostat
increases on
cold
Heat

47. Regulation of Blood Glucose Level Eat, digestion, breakdown starch = lots of glucose Absorbed by the body into the blood stream Blood glucose levels rise SIGNAL to Pancreas - secrete insulin HORMONE - signals body cells to absorb glucose which is changed into glycogen Blood glucose levels stabilize Excercise or don't eat Blood glucose levels drop SIGNAL to pancreas - secreates glucagon HORMONE - stimulates the cells to break down glycogen to glucose and release into the blood stream

48. River otter (endotherm)
Largemouth bass (ectotherm)
Ambient (environmental) temperature (°C)
Body temperature (°C) 40 30 20 10

49. Radiation is the emission of electromagnetic
waves by all objects warmer than absolute
zero. Radiation can transfer heat between
objects that are not in direct contact, as when
a lizard absorbs heat radiating from the sun.
Evaporation is the removal of heat from the surface of a
liquid that is losing some of its molecules as gas.
Evaporation of water from a lizard’s moist surfaces that
are exposed to the environment has a strong cooling effect.
Convection is the transfer of heat by the
movement of air or liquid past a surface,
as when a breeze contributes to heat loss
from a lizard’s dry skin, or blood moves
heat from the body core to the extremities.
Conduction is the direct transfer of thermal motion (heat)
between molecules of objects in direct contact with each
other, as when a lizard sits on a hot rock.